The recent order of 100 Boeing 737-900ERs by Delta Air Lines reflects an urgency by legacy carriers to replace ageing aircraft, but the airline’s decision to go with the -900ER does not preclude it from being an operator of the re-engined 737 Max.

Delta, which first announced the order on 25 August, said separately in a regulatory filing on 30 August that it is cancelling 126 existing options for 737-800s in exchange for an additional 30 options for the -900ER, on top of the 100 firm orders.

The SkyTeam carrier announced the order just days before Boeing rolled out the re-engined 737 Max, which the airframer said has already garnered 496 commitments from five carriers.